After a period of time the wheel cylinders will start to leak. When they do the braking force will diminish and, in extreme cases, could cause loss of braking. You probably won't know something is wrong until you notice the pedal is a lot lower than it used to be, or it slowly sinks as you hold it. If you have your brakes inspected at regular intervals, a leaking wheel cylinder will be caught before it has a chance to ruin your brake shoes.

There are two ways of dealing with a leaking wheel cylinder. One is to replace it, the other is to rebuild it. Neither one is really difficult to do. It just requires a little work and a couple of things to keep in mind as you do it. The choice to rebuild or replace is dependent on a couple of things. Usually it is faster to just replace the wheel cylinder. Another factor is the bleeder screw may be so deteriorated that opening it is impossible. That makes replacement the only option. Rebuilding is cheaper, but takes longer to do.

Before You Start:

Follow these instructions carefully. Read and be sure you understand them before you begin.

Gather together all of your tools and supplies before you begin.

Allow plenty of time to do the job so you don't have to hurry.

Remember that these are general instructions. For more detailed instructions pertaining to your specific vehicle, consult an appropriate repair manual.

Never work on a vehicle that is only supported by a jack. Use jack stands to support the vehicle while you work. Work on a solid, level surface. Never jack a car up on dirt or grass.

Check for any brake fluid leaks or cracked brake lines. Replace them as necessary.

Okay, let's put on some old clothes and get to work. Make sure that your car is parked on a level grade, rather than on any sort of hill or inclined driveway. Jack up the car and place your jack stands under the frame to support the vehicle. Block the wheels to prevent rolling. Make sure the new wheel cylinders are the same as the ones you are replacing. Most are interchangeable left to right, but some are for the left or right sides and can't be swapped around. And don't forget, wheel cylinders are replaced or rebuilt in pairs. If, for some reason, one side can't be rebuilt, then replace both. Don't rebuild one and replace the other.